The present invention is directed to a method and apparatus for assembling leads, electronic components and jackets to form jacketed electronic devices. More specifically, the present invention provides a method and apparatus for assembling jacketed electronic devices without requiring the devices to be taken from the heating system until finally assembled.
With the advent of miniaturization, electronic devices have been developed employing very small semiconductor dies which are in the form of small blocks. It is often required that these blocks or electronic components be associated with two leads extending from opposite sides of each component in order that the component may be integrated into an electronic system. Consequently, conductor leads have been developed which include a swaged end for mating with one side of such an electronic component. A thin wafer of solder may be employed to bond each conductor lead to the electronic component.
To assemble such electronic devices from leads and electronic components, a device, commonly referred to as a boat, has been developed. Such a boat generally includes a large number of heating cavities which each receive, in order, a first lead, a solder wafer, an electronic component, a second solder wafer and a second lead. The boat is of carbon which may be associated with an electrical supply to cause the boat to heat up. Heating of the boat allows the solder to melt and bond the leads on either side of each electronic component. Each assembled device is often fitted with a heat recoverable jacket or other covering following removal of the assembled device from the boat to provide protection, electrical isolation and structural strength.
Many difficulties have been experienced in the fabrication of such jacketed electronic devices. First, the handling of each electronic component with its leads is tedious, time consuming and expensive. Furthermore, it is necessary to allow for substantial cooling of the surrounding boat prior to removal of the assembled electronic device because solders generally experience low strength at elevated temperatures. This low strength increases the possibility that the bond between a lead and the electronic component may be disrupted during handling of the component or during the covering operation which follows the soldering step.